Dichotomous Choice Tests Research Articles

Salinity limits mosquitofish invasiveness by altering female activity during mate choice

Biological invasions of freshwater habitats are of increasing biological and economical concern, and both, salinity and parasites are considered to be key contributors to invasion success. Salinity, for example, influences the distribution of invasive mosquitofish (Gambusia holbrooki) and native killifish (Aphanius fasciatus) in Europe, with the latter now predominantly confined to high-salinity habitats. Here, we examined how salinity might affect female activity and preference for large and non-parasitized males in multiple populations of mosquitofish and killifish in Sardinia, Italy. We predicted that (1) females of both species would associate preferentially with larger and uninfected males, and that (2) female behavior in both species would be significantly influenced by salinity. We used dichotomous choice tests, in which we presented focal females with video animations of photos of the same male but differing in body size and presence/absence of an ectoparasite (Lernaea cyprinacea). We calculated female preference based on association time and quantified female inactivity as time spent in the central neutral zone during trials. Contrary to prediction 1, females did not prefer the large or uninfected male stimuli over their counterparts in any of the populations. However, while salinity did not significantly affect female preferences, it did significantly affect their activity, with mosquitofish becoming more inactive at higher salinities and killifish exhibiting the opposite pattern, matching prediction 2. These results suggest that salinity limits mosquitofish invasiveness by reducing their activity and thus provides a refuge for the Mediterranean killifish.

No geographical differences in male mate choice in a widespread fish, Limia perugiae.

Behavior, like most other traits, can have a spatial component, and variability of behavior at the population level is predicted. In this article, we explore male mate choice at this level. Male mate choice, while maybe not as common as female choice, is expected to evolve when males respond to significant variation in female quality and, for example, prefer females with higher fecundity. In fishes, higher fecundity is associated with larger body size, an easily measured trait. In this study, we investigated the presence of male mate choice for larger females in a widespread species of livebearing fish, Limia perugiae, while comparing preferences between populations. We hypothesized that environmental variation, for example, in the form of salinity, might result in population differences. Using dichotomous choice tests, we analyzed behavioral data for 80 individuals from 7 distinct populations from Hispaniola. We found that L. perugiae males significantly preferred large females, but there was no significant statistical variation between populations.

Social opportunities and mate preference improve breeding success in Caribbean iguanas

Conservation breeding of West Indian rock iguanas (Cyclura) has met with limited success historically. Many facilities witness high levels of aggression and mate incompatibility resulting in failed breeding introductions which often require animals to be separated. This may be due, in part, to lack of knowledge of how mate familiarity and preference affect reproductive outcomes in these species. We investigated whether social exposure during the pre-breeding season influenced copulation success, egg production, and breeding behaviors. Additionally, we examined whether mate preference, as determined by pre-mating dichotomous choice tests, increased these reproductive outcomes. Female rock iguanas that were socialized with males prior to breeding opportunities copulated with familiar males for longer periods of time than females that were not socialized. Socialization opportunities did not alter male reproductive success measurements or breeding behavior. Female rock iguanas introduced for mating to their preferred partners had a higher probability of successful copulations, higher average number of copulations, and less resting behavior during introductions than females mated to non-preferred males. Male mate preference had no effect on reproductive success measurements during mating introductions. These results indicate that socializing animals and providing mate choice opportunities increase breeding success of rock iguanas under managed care.

The attraction trick: males in early stages of disease become more chemically attractive to Nile tilapia (Oreochromis niloticus) females.

In aquatic systems, olfaction plays an important role in acquiring information about the social environment and influences important behaviours in various contexts, including predator avoidance, foraging, aggressive and reproductive behaviour and mate selection. As the presence of diseases might modify individual odour, fish may use the variability in conspecifics' odours as an indicator of the health status and infectious load of potential mates. Here, female Nile tilapia were tested for their ability to detect infected males and discriminate between bacterial infected and uninfected individuals by means of chemical cues. Females were allowed to choose between the odours of males infected by Aeromonas hydrophila bacteria and uninfected males. The findings show that female Nile tilapia initially showed a preference for infected males in terms of their first choice in a dichotomous choice test, but the total duration of time spent with the stimulus from infected males was not longer than that for the uninfected males. This may indicate that males at early stages of infection, i.e., without advanced clinical signs of infection, emit odours that allow them to enjoy the benefits of socialization when the infection is not yet detected by conspecifics. Thus, in the context of reproduction, males might attract female partners and have some chance of reproducing, before being avoided.

Smart mating: the cognitive ability of females influences their preference for male cognitive ability.

Cognitive abilities may be crucial for individuals to respond appropriately to their social and natural environment, thereby increasing fitness. However, the role of cognitive traits in sexual selection has received relatively little attention. Here, we studied 1) whether male secondary sexual traits (colour, courtship, and nest) reflect their cognitive ability, 2) whether females choose mates based on males' and their own cognitive abilities, and 3) how the interplay between secondary sexual traits and cognitive ability determines male attractiveness in the three-spined stickleback (Gasterosteus aculetaus). For this, we first evaluated the cognitive ability of sexually mature males and females in a detour-reaching task. Then, female preference was repeatedly assessed in a dichotomous-choice test, where the female was exposed to two males with contrasting performances (relatively good and bad) in the detour-reaching task. Female preference for better performing males was affected by the female's own cognitive ability. Females with relatively medium-low cognitive ability preferred males with high ability, whereas females with high ability showed no preference. We also found that males with higher cognitive abilities built more elaborated nests, but showed weaker red nuptial colouration. To our knowledge, this is among the first results that illustrate how cognitive traits of both sexes influence female mate preference, which has implications for the strength and direction of sexual selection.

Male Sexual Preference for Female Swimming Activity in the Guppy (Poecilia reticulata).

Simple SummaryIn our first experiment, we found that male and female guppies differ consistently in their swimming activity, both when alone and when together in heterosexual pairs, and that males, regardless of their own activity, show more sexual behaviours to more active females in these pairs. In the second experiment, we gave males the choice between a slow and a fast-moving virtual female and found that males prefer to associate with the fast-moving female. Both experiments together provide evidence that guppy males prefer faster moving females as mating partners over slower moving ones. Higher activity patterns may indicate health, fitness and receptivity and a mating preference for more active females can help males increase their own reproductive success.Mate choice that is based on behavioural traits is a common feature in the animal kingdom. Using the Trinidadian guppy, a species with mutual mate choice, we investigated whether males use female swimming activity—a behavioural trait known to differ consistently among individuals in many species—as a trait relevant for their mate choice. In the first experiment, we assessed male and female activity in an open field test alone (two repeated measures) and afterwards in heterosexual pairs (two repeated measures). In these pairs, we simultaneously assessed males’ mating efforts by counting the number of sexual behaviours (courtship displays and copulations). Male and female guppies showed consistent individual differences in their swimming activity when tested both alone and in a pair, and these differences were maintained across both test situations. When controlling for male swimming behaviour and both male and female body size, males performed more courtship displays towards females with higher swimming activity. In a second experiment, we tested for a directional male preference for swimming activity by presenting males video animations of low- and high-active females in a dichotomous choice test. In congruence with experiment 1, we found males to spend significantly more time in association with the high-active female stimulus. Both experiments thus point towards a directional male preference for higher activity levels in females. We discuss the adaptive significance of this preference as activity patterns might indicate individual female quality, health or reproductive state while, mechanistically, females that are more active might be more detectable to males as well.

Do chewing cues from drywood termites mediate recruiting for wood colonization?

AbstractDrywood termites, Cryptotermes brevis (Walker) (Isoptera: Kalotermitidae), are eusocial insects living and foraging in groups inside pieces of wood, in which they perform a suite of behavioral traits ranging from individual to coordinated group activities. Vibroacoustic cues play important roles in behavioral mediation during defense and foraging activities. However, termite societies also exhibit other relevant behaviors, including substrate selection for colony establishment, which has received little attention. Therefore, we tested the hypothesis that vibrational cues produced by termites inside pieces of drywood influence wood recruiting of conspecifics using dichotomous choice tests. In addition, we assessed whether the choice affects colony success (i.e., termite survival and wood consumption). Two behavioral activities were recognized among drywood termites colonizing wood galleries – walking and chewing. However, only the chewing cues overcome background noise, allowing acoustic signal characterization and playback tests; thus, they were the focus of our study. Overall, drywood termite groups exhibit random choice among wood‐testing unities, indicating that the chewing cues from the natural and/or playback signals are not used as a social trigger to mediate conspecific recruiting for wood preference and colonization. Nonetheless, the establishment of termite colonies in infested vs. non‐infested wood pieces led to better termite performance in the former, exhibiting higher wood consumption and survival.

Male rainbow darters (Etheostoma caeruleum) prefer larger conspecific females

Female mate choice is a well studied mechanism of sexual selection that can affect the evolution of male secondary sexual traits. However, males also exhibit selective mate choice in some animals, which can affect the evolution of female phenotypes. We tested for evidence of intraspecific male mate choice in the Rainbow Darter (Percidae: Etheostoma caeruleum). Males of numerous darter species have been shown to prefer conspecific over heterospecific females; however, intraspecific preferences in males have not yet been demonstrated in this genus. This study investigated male preference for indicators of female fecundity, specifically female size. We found that male Rainbow Darters prefer larger females, both in dichotomous choice tests, when access between individuals was prevented, and in unrestricted behavioral tests with full access to females. Notably, however, the dichotomous trials were not repeatable; males only displayed a significant preference for larger females in the first dichotomous trial and in the unrestricted trial. We discuss our results in light of experimental methods and the role of male mate choice in sexual selection.

Does geographical isolation influence group recognition and social preference in an invasive lizard?

AbstractThe formation of aggregations is fundamental to animal organization and has been shown to confer an evolutionary advantage. Conspecific attraction often prompts the formation of social groups yet not all individuals are equally attracted to others of their own species. The decision to aggregate with or avoid a particular individual is based upon class‐specific signals that serve to differentiate among members and non‐members. Given that signal divergence may be driven by local adaptation, disjunct populations could potentially have evolved distinct recognition systems adapted to their own ecological conditions. Several studies have shown that individuals of a species are capable of discriminating between such classes as sex, mate, kin, and familiar. Yet research exploring conspecific attraction between populations is lacking. Invasive species offer a unique opportunity to determine the consequences of geographic isolation on recognition systems and social preferences, as these genetically distinct native‐range source populations have the potential to undergo secondary contact within the invaded region. To this end, we used an invasive lizard species, the delicate skink (Lampropholis delicata), to investigate conspecific recognition and attraction among individuals from two identified source populations that vary both genetically and morphologically. Our results of the dichotomous choice tests indicate that L. delicata did not differ in the level of social attraction expressed towards individuals from either population. It is unclear whether these findings are due to an inability to discriminate between local and foreign lizards using visual cues or instead that attraction is not based upon an individual's population origin but rather some other factor such as thermoregulatory requirements. Understanding the role that conspecific attraction plays in the invasion process will enable us to better predict the impacts of biological invasions. Future studies should consider using other sensory modalities and investigate the physiological benefit of grouping.

Transmission risk predicts avoidance of infected conspecifics in Trinidadian guppies.

Associating with conspecifics afflicted with infectious diseases increases the risk of becoming infected, but engaging in avoidance behaviour incurs the cost of lost social benefits. Across systems, infected individuals vary in the transmission risk they pose, so natural selection should favour risk-sensitive avoidance behaviour that optimally balances the costs and benefits of sociality. Here, we use the guppy Poecilia reticulata-Gyrodactylus turnbulli host-parasite system to test the prediction that individuals avoid infected conspecifics in proportion to the transmission risk they pose. In dichotomous choice tests, uninfected fish avoided both the chemical and visual cues, presented separately, of infected conspecifics only in the later stages of infection. A transmission experiment indicated that this avoidance behaviour accurately tracked transmission risk (quantified as both the speed at which transmission occurs and the number of parasites transmitting) through the course of infection. Together, these findings reveal that uninfected hosts can use redundant cues across sensory systems to inform dynamic risk-sensitive avoidance behaviour. This correlation between the transmission risk posed by infected individuals and the avoidance response they elicit has implications for the evolutionary ecology of infectious disease, and its explicit inclusion may improve the ability of epidemic models to predict disease spread.

Preferences of age-0 white sturgeon for different colours and strobe rates of LED lights may inform behavioural guidance strategies

Many populations of migratory fish species, including white sturgeon (Acipenser transmontanus Richardson), are threatened due to modification of riverine systems and may experience downstream displacement or mortality at water intake structures. Efforts to reduce the impacts of these structures are beginning to incorporate behavioural guidance, where the sensory capabilities of fishes are exploited to repel them from high-risk areas or attract them towards desirable paths. Artificial lighting has been tested before, but consisted of single-spectrum lights. Using a new programmable LED-based light guidance device (LGD), we exposed age-0 white sturgeon to light strobing at 1 Hz, 20 Hz, or constant illumination with colours (green, red, blue) matching the absorbance maxima of their retinal photopigments. The behavioural responses of the sturgeon were assessed using y-maze dichotomous choice tests under both day (light) and night (dark) conditions. Sturgeon demonstrated positive phototaxis under both day and night conditions, and approached the LGD more often when light was continuous or strobing at 20 Hz compared to strobing at 1 Hz. Green light elicited the greatest rates of attraction overall. The combination of strobing and colour may help to protect imperiled fish from waterway development and serve as an effective form of mitigation at hydropower facilities and other human infrastructure where fish may be entrained or impinged.

Selection for relative brain size affects context-dependent male preference for, but not discrimination of, female body size in guppies.

Understanding what drives animal decisions is fundamental in evolutionary biology, and mate choice decisions are arguably some of the most important in any individual's life. As cognitive ability can impact decision making, elucidating the link between mate choice and cognitive ability is necessary to fully understand mate choice. To experimentally study this link, we used guppies (Poecilia reticulata) artificially selected for divergence in relative brain size and with previously demonstrated differences in cognitive ability. A previous test in our female guppy selection lines demonstrated the impact of brain size and cognitive ability on information processing during female mate choice decisions. Here, we evaluated the effect of brain size and cognitive ability on male mate choice decisions. Specifically, we investigated the preference of large-brained, small-brained and non-selected guppy males for female body size, a key indicator of female fecundity in this species. For this, male preference was quantified in dichotomous choice tests when presented with dyads of females with small, medium and large body size differences. All types of males showed a preference for larger females but no effect of brain size was found in the ability to discriminate between differently sized females. However, we found that non-selected and large-brained males, but not small-brained males, showed a context-dependent preference for larger females depending on the difference in female size. Our results have two important implications. First, they provide further evidence that male mate choice also occurs in a species in which secondary sexual ornamentation is present only in males. Second, they show that brain size and cognitive ability have important effects on individual variation in mating preference and sexually selected traits.

Behavioural guidance of yellow-stage American eel Anguilla rostrata with a light- emitting diode device

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 35:159-168 (2018) - DOI: https://doi.org/10.3354/esr00884 Behavioural guidance of yellow-stage American eel Anguilla rostrata with a light-emitting diode device Chris K. Elvidge1,4,*, Matthew I. Ford1, Thomas C. Pratt2, Karen E. Smokorowski2, Michael Sills3, Paul H. Patrick3, Steven J. Cooke1 1Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, K1S 5B6, Canada 2Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada, Sault Ste Marie, ON, P6A 2E5, Canada 3ATET-TECH Incorporated, Thornhill, ON, L4J 6X8, Canada 4Present address: Department of Biology, University of Eastern Finland, PO Box 111, Joensuu, 81010 Finland *Corresponding author: chris.k.elvidge@gmail.com ABSTRACT: Providing safe downstream passage for outmigrating freshwater eels around hydroelectric facilities, especially on large river systems, is a daunting challenge. With engineering limitations on the installation of physical barriers, behavioural guidance research is needed to steer outmigrating eels towards safe passage or collection facilities. We exposed late, yellow-stage American eel Anguilla rostrata to different colours and strobing frequency of light-emitting diode (LED) light, or to unlit control trials, in y-maze dichotomous choice tests. Eels demonstrated initial attraction towards the y-maze structure and entered the dark (control) side more often and for a longer duration compared to the illuminated side. Blue light strobing at 30 Hz elicited the greatest initial avoidance response and eels spent less time on the light side with this treatment, and we recommend that this setting be tested further under field conditions. Although the initial avoidance of all light settings attenuated over the 5 min observations, this attenuation may be less relevant when eels are engaged in active migration, and thus may provide a viable means of guiding eels to safe outmigration paths. KEY WORDS: Hydropower · Turbines · Outmigration · Light guidance device · Strobing lights · LED Full text in pdf format PreviousNextCite this article as: Elvidge CK, Ford MI, Pratt TC, Smokorowski KE, Sills M, Patrick PH, Cooke SJ (2018) Behavioural guidance of yellow-stage American eel Anguilla rostrata with a light-emitting diode device. Endang Species Res 35:159-168. https://doi.org/10.3354/esr00884 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 35. Online publication date: March 15, 2018 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2018 Inter-Research.

Context-dependent female mate choice maintains variation in male sexual activity.

The existence of individual variation in males' motivation to mate remains a conundrum as directional selection should favour high mating frequencies. Balancing selection resulting from (context-dependent) female mate choice could contribute to the maintenance of this behavioural polymorphism. In dichotomous choice tests, mosquitofish (Gambusia holbrooki) females preferred virtual males showing intermediate mating frequencies, reflecting females' tendencies to avoid harassment by highly sexually active males. When tested in the presence of a female shoal—which protects females from male harassment—focal females showed significantly stronger preferences for high sexual activity. A trade-off between (indirect) benefits and (direct) costs of mating with sexually active males probably explains context-dependent female mate choice, as costs depend on the social environment in which females choose their mates. No preference was observed when we tested virgin females, suggesting that the behavioural pattern described here is part of the learned behavioural repertoire of G. holbrooki females.

Context-dependent preferences vary by multicomponent signals in a swordtail

Female mating preferences can be both context dependent and based on the assessment of multicomponent male signals. Here, we assess the social context dependence of female mating preferences for two components of a male's multicomponent signal. We dissected the visual signal of male Xiphophorus nigrensis swordtails, a species in which males vary by both size and degree of courtship, to test (1) how the identity of males in a given choice influences female mating preferences and (2) how females perceptually integrate a male's multicomponent signal. We used validated male animations that generate repeatable female responses to test mating preferences for size and courtship vigour, separately and together, using dichotomous choice tests. When keeping courtship vigour constant, females discriminated between males only when there was a large size difference between them. When keeping size constant, the identity of males in a choice reversed a preference for a vigorously courting male. We found no evidence that females perceptually bind the separate components of a male's signal additively. However, females were faster to approach males when the males varied in both size and courtship than when the males only varied in size, perhaps favouring the evolution of multicomponent signals in males.

Risk sensitivity, phylogenetic reconstruction, and four chimpanzees.

Sensitivity to variance, or risk, has been considered elementary to economic decision making, featured prominently in discussions of primate species-typical behaviors and phylogeny, and heralded as a challenge to deterministic foraging theory. Most risk sensitivity studies involve dichotomous choices and small spatial scales, providing only limited bases for predicting how variance information might be used across contexts. We examined foraging risk-sensitivity in four chimpanzees (Pan troglodytes) which were presented containers associated with particular mean food rewards/variances. Preferences were measured via indoor dichotomous choice tests. Subsequent tasks, designed to assess how well these preferences held up across situations, involved a differing food type, rank-ordering arrays of containers, and/or recovering them in a large outdoor testing area. In addition, some variations involved memory for containers previously observed being hidden. Risk preferences varied by subject, experimental context, reward type, and mean reward quantity. In rank-ordering experiments, under the reward contingencies utilized, mean food quantity was a better predictor of selection order than variance. These results bring into question arguments that species-typical primate risk traits-in the sense of enduring, generalized dispositional features of organisms-have been firmly identified, and suggest that many popular experimental strategies are alone inadequate for reconstructing risk-related traits in primate/human evolution. Models from classical foraging theory, which do not address variance, have likely been successful because they include crucial variables with robust predictive value. Determining the importance of variance to naturalistic decision-making, on the other hand, will require further testing in a wide range of experimental and observational contexts.

Female mating preferences for outbred versus inbred males are conditional upon the female's own inbreeding status

Inbreeding occurs when relatives mate with each other, and it often has detrimental effects for the fitness of any resulting offspring. It is an important issue in ecology and evolutionary biology with profound implications for genetic variation and the evolution of mating systems and reproductive strategies. For example, inbreeding may shape mate choice through the avoidance of outbred, related individuals to prevent inbreeding, or through the avoidance of inbred, unrelated individuals that have been produced through inbreeding. Although the former has been studied extensively, little is known about mating preferences based on the inbreeding status of potential partners. It is also unclear whether these mating preferences are influenced by the inbreeding status of the choosing sex. Here, we examined female mating preferences for outbred versus inbred males using dichotomous choice tests in the burying beetle Nicrophorus vespilloides. We found that these mating preferences were conditional upon the female's own inbreeding status: inbred females preferentially mated with outbred males, whereas outbred females did not show such a preference. Our findings suggest that inbred males suffer reduced mating success only when interacting with inbred females. In species where this is the case, the fitness costs of inbreeding with respect to male mating success will therefore depend on the frequency of inbred females relative to outbred females, which depends on the rate of inbreeding in the population.

Male mate choice in the Trinidadian guppy is influenced by the phenotype of audience sexual rivals

In populations with male mate-choice copying, males may mitigate their risk of sexual competition by reducing their preference for a particular female in the presence of sexual rivals (audience). Because of the cost of missed mating opportunities from such an audience effect, males should reduce their mating preference to a greater extent in the presence of more sexually competitive rivals compared with less competitive ones. We tested this hypothesis using the Trinidadian guppy (Poecilia reticulata). We compared a focal male's baseline mating preference for either of 2 stimulus females, which differed in overall body size, in the absence of any sexual rival to his preference for the same females in the presence of a sexual rival using dichotomous-choice tests. Focal and audience males differed in body length and proportion of their body covered in orange and black pigmentation. In the presence of a larger rival, focal males exhibited a greater reduction in preference for their initially preferred female compared to focal males in the presence of a smaller rival, irrespective of whether the latter male was more or less ornamented than the focal. The strength of the initial mating preference of focal males and the magnitude of the audience effect were significantly positively correlated when the audience male was larger than the focal male. Male guppies are thus sensitive to the phenotype of nearby males and alter their preference for a particular mate to a greater extent in the presence of relatively larger eavesdropping males compared to smaller ones.

Social environment affects female preference for male body color during development in artificially selected varieties of Poecilia latipinna

This study provides evidence for an effect of social environment on color morph preference during development in two artificially selected varieties of the live-bearing fish Poecilia latipinna. Black-colored females reared exclusively in the presence of white-colored adults preferred to associate with white vs black males when tested using a standard dichotomous choice design. Similarly, white females reared exclusively in the presence of black adults showed a preference for black males in identical dichotomous choice tests. However, both black and white females when reared separately in the presence of a mix of black and white adults showed no preference for either male color variety. A second round of testing revealed that their preferences (or lack thereof), although significantly weaker, persisted for at least a week after the initial tests during which the model groups were altered; groups reared in the presence of opposite-colored adults were exposed to mixed-color adults, while groups reared in the presence of mixed-color adults were exposed to opposite-color models. Taken together, these data indicate that the females’ social environment during the first 2 months of life affected the development of preferences for male body color and further suggest such social learning could potentially influence mate and/or shoaling preferences for color and perhaps other traits in natural populations of P. latipinna.

Imprinting can cause a maladaptive preference for infectious conspecifics.

Recognizing and associating with specific individuals, such as conspecifics or kin, brings many benefits. One mechanism underlying such recognition is imprinting: the long-term memory of cues encountered during development. Typically, juveniles imprint on cues of nearby individuals and may later associate with phenotypes matching their 'recognition template'. However, phenotype matching could lead to maladaptive social decisions if, for instance, individuals imprint on the cues of conspecifics infected with directly transmitted diseases. To investigate the role of imprinting in the sensory ecology of disease transmission, we exposed juvenile guppies,Poecilia reticulata, to the cues of healthy conspecifics, or to those experiencing disease caused by the directly transmitted parasite Gyrodactylus turnbulli In a dichotomous choice test, adult 'disease-imprinted' guppies preferred to associate with the chemical cues of G. turnbulli-infected conspecifics, whereas 'healthy-imprinted' guppies preferred to associate with cues of uninfected conspecifics. These responses were only observed when stimulus fish were in late infection, suggesting imprinted fish responded to cues of disease, but not of infection alone. We discuss how maladaptive imprinting may promote disease transmission in natural populations of a social host.